Hex Socket Bolt Black Key Features
Black Oxide Finish: Provides basic rust protection with a matte black finish, reducing light reflection and
improving wear resistance and lubricity, suitable for moderately corrosive environments.
Internal Hex Socket Drive Design: Cylindrical head with an embedded hexagonal slot, driven by an Allen
key, facilitating high-torque installation in confined spaces and preventing external damage.
Material and Strength: Commonly used alloy steel or stainless steel, high strength grade (e.g., 12.9 grade),
fatigue resistant; conforms to DIN 912 and ISO 4762 standards.
Various Specifications: Diameter M2-M36, length 5mm-300mm, supports full thread or shoulder designs.
Advantages: Aesthetically pleasing and discreet, high torque efficiency, but the coating is relatively thin,
unsuitable for extremely humid environments.
Working Principle
Drive Fit: The Allen key is inserted into the hexagonal slot of the head, rotation applies torque, aligning
the thread with the nut or internal threaded hole, generating axial force.
Preload Generation: Torque is converted into clamping force. The black oxide layer reduces friction,
improves efficiency, and distributes stress to prevent loosening.
Protection Mechanism: The black oxide forms a phosphate layer, providing mild corrosion protection;
the principle involves mechanical interlocking and surface lubrication.
Installation Control: Precise force is applied using a torque wrench to avoid overtightening and damaging
the coating or threads.
Product Applications
Machinery Manufacturing: Secures machine tool components, gears, or precision instruments; the black
coating reduces glare and improves safety.
Automotive and Motorcycles: Assembles engines, suspensions, or frames; vibration-resistant and
aesthetically pleasing.
Electronic Equipment: Connects computer hardware, circuit boards, or drones; the stainless steel version
is corrosion-resistant.
Furniture and DIY: Assembles modern furniture or bicycles; the understated appearance enhances the
overall quality.
Aerospace and Military: Used in aircraft structures or equipment; high strength and corrosion resistance
make it suitable for harsh environments.
